The invention relates generally to medical devices and more particularly to a surface neuroprosthesis device and method for functional electrical stimulation of a limb.
A surface neuroprosthesis device, also referred to as an orthosis device, such as a splint, cuff or garment, can be used in conjunction with an electrode to provide electrical stimulation of, for example, paralyzed limbs in therapeutic exercises and for generating limb function during functional electrical stimulation (FES).
FES is a means to communicate with the neuromuscular system for producing contraction in muscles or sensory input to the body. FES can be used in neuroprostheses for restoring active function to, for example, paralyzed or plegic body limbs in patients suffering disease or trauma to the central nervous system, in neurological conditions such as stroke, spinal cord injury, head injury, cerebral palsy and multiple sclerosis. Surface FES systems use controlled electrical currents through electrodes placed on the surface of the body, to trigger contraction from muscles underlying the electrode or to input sensory stimulus. Surface neuroprostheses can coordinate the FES-activation of several muscles of the limb alone, or in coordination with voluntary activation of muscles under natural neurological control.
Surface neuroprostheses are used for functional activities such as walking, standing, gripping/releasing objects, etc. Known devices for use in surface electrical stimulation that have been developed for activating specific body sites include, for example, dropfoot systems, which activate the ankle joint, modifying hemiplegic gait; hybrid FES-orthosis systems for restoring gait in spinal cord-injured patients, and systems for therapeutic activation and functional restoration of the hand.
Some neuroprosthesis devices based on FES have been developed for activating specific sites of the body by stimulating the muscles to contract and relax. Such devices for the lower limb include gait modification systems, such as a dropfoot system that can activate the ankle joint to prompt dorsiflexion, and systems that can activate the knee joint. Some neuroprosthesis devices based on FES are used to stimulate other limbs, such as arms.
In many of the known FES devices, the neuroprosthesis device is limited for use at a single location on the patient's body to provide electrical stimulation to a particular nerve, muscle or muscle group. In addition, many known FES devices have a preset size (e.g., length and/or circumferential dimension) to fit a patient's limb.
Thus, there is a need for a neuroprosthesis device configured for use in the electrical stimulation of more than one nerve, muscle or muscle group and that can be easily moved by a patient to different desired treatment locations. There is also a need for a neuroprosthesis device for use in the electrical stimulation of a nerve, muscle or muscle group that can be adjusted to accommodate different types of limbs (e.g., arms, legs, etc.) and patients having different sized limbs.